This invention relates to specific types of metallocenes. In another aspect, this invention relates to the polymerization of olefins using such metallocenes.
It has been recognized that varying the substituents of metallocenes can affect the manner in which the materials act as catalysts in the polymerization of olefins. The present invention is based upon the discovery of a new class of unbridged metallocenes that are suitable for use as catalysts in the polymerization of olefins.
The present invention concerns an unbridged metallocene of a transition metal selected from the group consisting of zirconium, titanium, and hafnium having two substituted indenyl groups, one indenyl group being substituted in the 2 position by an aromatic substituent selected from phenyl and phenyl alkyl radicals in which there are 1 to 3 carbon atoms between the phenyl group and the indenyl group, and the other indenyl group being substituted in either the 1 position or 2 position by a non-aromatic substituent selected from alkyl groups having 2 to 6 carbon atoms and terminally unsaturated alkene groups having 2 to 6 carbon atoms. The invention is also directed to using such metallocenes in the polymerization of olefins.